Romina Libster: The power of herd immunity

How do vaccines prevent disease — even among people too young to get vaccinated? It’s a concept called “herd immunity,“ and it relies on a critical mass of people getting their shots to break the chain of infection. Health researcher Romina Libster shows how herd immunity contained a deadly outbreak of H1N1 in her hometown. (In Spanish with subtitles.) TEDTalks is a daily video podcast of the best talks and performances from the TED Conference, where the world’s leading thinkers and doers give the talk of